Ocular Hypertension and Glaucoma After Pars Plana Vitrectomy: A Systematic Review and Meta-analysis.

Topic: To evaluate whether pars plana vitrectomy (PPV) increases the risk of ocular hypertension (OHT) and glaucoma, with particular focus on lens status as a risk modifier.

Clinical relevance: OHT and glaucoma are major complications that can threaten vision and require lifelong management. While PPV is a standard treatment for vitreoretinal disease, concerns exist about its long-term effects on intraocular pressure (IOP) and glaucoma, particularly in pseudophakic eyes, where the natural lens barrier is absent. No clear, quantitative synthesis currently informs risk stratification in this context.

Methods: The protocol for this systematic review and meta-analysis was prospectively registered in PROSPERO (CRD42024541683), and data reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eligible studies were randomized or nonrandomized comparative studies reporting OHT or glaucoma after PPV in adults. We last searched Ovid MEDLINE, Ovid EMBASE, and Web of Science on 25 May 2024. Two reviewers independently conducted screening, data extraction, and ROBINS-I risk of bias assessment. Meta-analyses were performed using generalized linear mixed-effects models. Publication bias and heterogeneity were assessed. The ROBINS-I tool was used to assess the risk of bias in nonrandomized studies, and the certainty of evidence was evaluated using GRADE. Numbers needed to treat for harm (NNTH) were calculated using standard formulas as recommended in the Cochrane Handbook to enhance the clinical interpretability of the results.

Results: Forty-one observational studies (54,006 eyes) were included. The pooled absolute risk for post-PPV OHT was 5.6% (95%CI: 3.1-9.9; I² = 94.6%; low-certainty), and for glaucoma, 3.9% (95% CI, 2.0-7.2; I² = 94.4%; low-certainty). Pseudophakic eyes had threefold higher odds of OHT compared to phakic eyes (OR, 3.2; 95%CI: 1.0-9.9; I² = 75.1%; NNTH, 8; very low-certainty) and nearly twelvefold higher odds of glaucoma (OR, 11.81; 95%CI: 4.2-33.6; I² = 0%; NNTH, 10; moderate-certainty).

Conclusions: PPV is associated with clinically meaningful risk of OHT and glaucoma, especially in pseudophakic eyes. Despite limitations from nonrandomized data and heterogeneity, these findings highlight lens status as a key modifier of post-PPV risk and support tailored surgical planning and postoperative monitoring.